While the small community of adherents to strict Islam are being courted by Sunni and Shiite rivals, many worry they could bring Al Qaeda into the Lebanon conflict.
Fights between Sunnis and Alawites highlight challenges facing a sectarian-reconciliation deal signed this week.
Lebanese President Michel Suleiman's visited Damascus Wednesday, raising the prospect that perhaps hundreds of detainees in Syria will be released.
Fighting in Tripoli is indicative of rising Sunni-Shiite tensions as the formation of a new government hits an impasse. Religious leaders called for calm Wednesday.